Productivity trance
I discovered a number of years ago that playing one track of music in an endless loop helped me write the difficult first draft. Some writers and coders use white noise, but another group (I am one) prefer a single musical track in a loop. The kind of music varies by person (I use one specific Russian choir hymn); after a dozen loops the music disappears and what I get is a feeling of comfort, which helps me focus for hours while it repeats. Try it with your song. — KK